- Determination and elimination of excess wall moisture
- Removing old wallpaper
- Strengthening and priming the surface
- Underlay application
Determination and elimination of excess wall moisture
It is not difficult to understand that the wall surface is wet. It is determined by the dark color of the concrete. If you cannot determine the humidity in this way, then you need to glue a little film to the wall. With high humidity, condensation should appear on the back of the film. No wallpaper can be glued to such a surface, because neither paper nor vinyl wallpaper can stick to a wet base. In addition, any wall decoration will also fail if the wall is wet..
There are several external signs of excessive wall moisture:
- Peeling wallpaper
- Mold on the walls
- Peeling paint and plaster
After determining the causes of excess moisture and eliminating them, you can prepare the wall for wallpapering. First you need to check the surface for hardness. This is done by scratching with a hard object. If after this no delamination appears, then the surface is sufficiently hard. It is also necessary to clean the wall from chalk residues. If, after holding it along the wall, there is no white coating on the hand, then the wall is clean enough.
Removing old wallpaper
Old wallpaper layers must be removed from the wall. If there are glue or waste paper residues on the wall, they must be removed as well. For this, a spatula is usually used. The walls are moistened with warm water and detergent.
To get wet old wallpaper more quickly, you can notch it with a spatula. A needle roller and other tools are also used for this, which allow violating the integrity of the wallpaper. If the wallpaper is quite thick, then an electric drill can be used, on which a special grinding wheel is mounted. After this circle, a special primer is applied with special solvents. This solvent can be sprayed on by deliberately peeling back the top layer of the wallpaper. This will prevent damage to the plaster underneath the wallpaper. Always shoot from top to bottom. Currently, there are wallpapers on sale that can delaminate. That is, the upper layer of this wallpaper can be easily removed from the wall, and the wallpaper is glued to the lower layer..
Strengthening and priming the surface
After cleaning the walls, inspect them. If there are large cracks in the plaster, then they should be reinforced with a special synthetic fabric, but if the plaster is already crumbling, then it should also be removed. After that, a primer must be applied to the wall surface. Most surfaces require only a protective primer. But drywall boards must be strengthened with a special cushioning cloth before priming. If the surface of the boards is too smooth, then it must be coated with a contact primer..
Remains of paint or varnish on the wall must be checked for strength. If the paint “sits” firmly, then such a surface must be cleaned of dirt, if the surface is smooth, then roughen it, for example by grinding. Small cracks and the like must be putty. After that, the surface must be strengthened with a primer..
If the paint peels off, then it must be completely removed..
Some wallpapers require a backing. This allows you to wallpaper the wall with better quality. Previously, ordinary newspapers were glued instead of a backing. Now on sale there is roll waste paper. Depending on the wallpaper, a different substrate is used. For thin – thin, for thick – thick. It is not necessary to paste over the walls with a backing like wallpaper: it must be glued horizontally. This helps to avoid the backing seams getting caught in the wallpaper seams. It is best to glue the backing from the top corner of one side of the room. The length of the backing sheet should be equal to the length of the wall with a spade on the wall, about 12 mm. Once glued, the backing dries in 24 hours. After that, you can glue the wallpaper itself on it..